Low Melt Toner Core-Shell Structure for Humidity Stability

The patent applies local quality by creating a core-shell structure where the crystalline polyester is confined to the core region and the amorphous polyester forms the shell layer. This spatial differentiation ensures that the crystalline material provides low melting temperature from the core while the amorphous shell prevents surface migration, thereby maintaining charging performance even in high temperature and humidity conditions.

The patent implements the nested doll principle by placing the crystalline polyester material inside the amorphous polyester shell, creating a core-shell structure. The crystalline core is nested within the amorphous shell, which acts as a protective barrier. This nesting configuration allows the inner crystalline material to lower the overall melting temperature while the outer amorphous layer prevents the crystalline material from migrating to the surface and interfering with charging properties.

The patent applies preliminary action by forming the amorphous polyester shell during the toner particle formation process itself, rather than as a subsequent separate step. The emulsion aggregation method inherently creates the core-shell structure as the particles form, with the amorphous polyester naturally forming the outer shell. This preliminary formation of the protective shell during manufacturing avoids the need for additional post-processing steps to apply a shell coating.

The patent merges the low melting temperature function and the charging performance protection function into a single integrated core-shell structure. The crystalline core and amorphous shell are formed together in one manufacturing process through emulsion aggregation, combining multiple functions (low melting point provision and surface protection) into a unified structure rather than requiring separate components or steps.